"So, distinguished delegates, you have to ask yourself a question," Netanyahu stated point blank to the Assembly members. "Why did Iran keep a secret atomic archive and a secret atomic warehouse?... The reason Iran didn't destroy its atomic archive and its atomic warehouse is because it hasn't abandoned its goal to develop nuclear weapons. In fact, it planned to use both of these sites in a few years when the time would be right to break out to the atom bomb. But ladies and gentlemen, rest assured, that won't happen. It won't happen because what Iran hides Israel will find."

Netanyahu said the Iranian warehouse includes technology for Iran's nuclear initiative, remarking that the Islamic Republic "took this radioactive material and spread it around Tehran like Nutella."

Netanyahu said the regime removed 33 pounds of radioactive material from the facility, which contained up to 600,000 pounds of nuclear material, last month. The Israeli prime minister asked the International Atomic Energy Agency to inspect the facility.

"I have a message for tyrants of Tehran-Israel knows what you're doing," Netanyahu said. He added that Israel will continuously counter Iran and "also in Syria and also in Iraq."

"Hezbollah is using the innocent people of Beirut as human shields," said Netanyahu, holding up a photo of a missile site beneath a soccer stadium. "Israel also knows what you are doing."

Netanyahu's remarks come a day after meeting with U.S. President Donald Trump on the sidelines at the U.N. event, with the Israeli leader saying afterwards that he was "very pleased" with the outcome. They discussed peace negotiations with the Palestinians and the situation in Syria, among other regional issues.